Systems and methods for checking status of a pressure transducer

A controller for a gas furnace system including a draft inducer having a motor, a pressure transducer positioned to sense a pressure within a conduit and output signals proportional to the sensed pressure, and a pressure switch positioned to sense the pressure within the conduit, the pressure switch having a first state and a second state, and configured to be in the first state when the sensed pressure is below a predetermined pressure and to switch to the second state when the sensed pressure reaches or exceeds the predetermined pressure, the controller comprising a processor programmed to:

• receive pressure signals output by the pressure transducer;
• receive signals indicating whether the pressure switch is in the first state or the second state;
• control the motor of the draft inducer in response to a call for heat;
• determine a first status of the pressure transducer as reliable, unreliable, or questionable at a first time based on the received pressure signals from the pressure transducer, the signals indicating whether the pressure switch is in the first state or the second state, and a first status of the motor of the draft inducer at the first time, wherein a determination that the first status is questionable indicates the pressure transducer is less reliable than if the first status was reliable and the pressure transducer is more reliable than if the first status was unreliable;
• continue operation of the motor of the draft inducer when the first status of the pressure transducer indicates that the pressure transducer is reliable;
• output an alert or warning and continue operation of the motor of the draft inducer when the first status of the pressure transducer indicates that the pressure transducer is questionable;
• and
• stop operation of the motor of the draft inducer when the first status of the pressure transducer indicates that the pressure transducer is unreliable.

A method of controlling a gas furnace system comprising:

• controlling a motor of a draft inducer coupled to a conduit to increase a speed of the motor from a stopped condition in response to a call for heat;
• receiving pressure signals output by a pressure transducer responsive to pressure in the conduit;
• receiving signals indicating whether a pressure switch responsive to pressure in the conduit is in a first state or a second state;
• determining a first status of the pressure transducer as reliable, unreliable, or questionable at a first time based on the received pressure signals from the pressure transducer, the signals indicating whether the pressure switch is in the first state or the second state, and a first status of the motor of the draft inducer at the first time, wherein a determination that the first status is questionable indicates the pressure transducer is less reliable than if the first status was reliable and the pressure transducer is more reliable than if the first status was unreliable;
• continuing operation of the motor of the draft inducer when the first status of the pressure transducer indicates that the pressure transducer is reliable;
• outputting an alert or warning and continuing operation of the motor of the draft inducer when the first status of the pressure transducer indicates that the pressure transducer is questionable;
• and
• stopping operation of the motor of the draft inducer when the first status of the pressure transducer indicates that the pressure transducer is unreliable.